An automatic detector for low-power pulse solenoid switch state

Abstract

This invention relates to the field of automatic detection of the on / off status of solenoid valves, specifically to an automatic detector for the on / off status of low-power pulse solenoid valves. The detector includes a signal acquisition module connected in series with the control circuit of the pulse solenoid valve to acquire differential current signals in the control circuit and convert these signals into stable voltage signals. A microprocessor module is connected to the output of the signal acquisition module and has a built-in Fast Fourier Transform algorithm for determining the on / off status and fault status of the solenoid valve based on the received voltage signal. This automatic detector for the on / off status of low-power pulse solenoid valves can be installed non-destructively without altering the original equipment. No structural or circuit modifications to the original controller or pulse solenoid valve are required; the detector simply needs to be connected in series with the existing control circuit to operate, significantly reducing deployment barriers and modification costs.

Description

Technical Field

[0001] This invention belongs to the field of automatic detection of the switching status of solenoid valves, and specifically relates to an automatic detector for the switching status of low-power pulse solenoid valves. Background Technology

[0002] Pulse solenoid valves are widely used in urban gas transmission and distribution systems, industrial and commercial gas equipment, and residential gas appliances. They are key actuators for gas safety shut-off and flow control. When a gas alarm detects a gas leak, it controls the solenoid valve to engage or disengage to shut off the gas pipeline, preventing further gas leakage from causing fires, explosions, and other safety accidents. However, existing solenoid valve control and status detection technologies in the gas industry have the following prominent problems. In existing gas systems, controllers can only issue valve opening or closing commands, but cannot confirm whether the valve has been successfully opened or closed. Even if the user receives an alarm and issues a shut-off signal, if the solenoid valve fails to actually close due to coil aging and corrosion, valve core jamming, or other reasons, the controller cannot detect this abnormal state. At this time, gas continues to leak without the system's knowledge, leading to serious safety hazards. Traditional solenoid valve status detection solutions typically require structural functional modifications to the solenoid valve body or controller, such as adding auxiliary contacts, mechanical position indicators, or pressure sensors. This necessitates redesigning molds and altering the internal structure of the solenoid valve, resulting in long development cycles, high modification costs, and poor versatility. Furthermore, such modifications are often difficult to implement non-destructive installation, hindering rapid deployment without affecting the normal operation of existing systems. Moreover, current gas alarms primarily diagnose solenoid valve faults by detecting the high and low voltage levels in the detection circuit, lacking real-time, online, and proactive monitoring of the solenoid valve's own status. This means that potential solenoid valve faults cannot be detected and warned of in a timely manner during gas usage, creating a "last mile" monitoring blind spot in the gas safety system. Therefore, there is an urgent need for an automatic detection instrument for the on / off status of low-power pulse solenoid valves. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art, such as the inconvenience of quickly detecting the switching status of low-power pulse solenoid valves and the long development cycle and poor versatility of existing detectors, so as to realize an automatic detector for the switching status of low-power pulse solenoid valves.

[0004] To achieve the above-mentioned objectives, the technical solution of this invention is: an automatic detector for the switching state of a low-power pulse solenoid valve, comprising: The signal acquisition module is used to be connected in series in the control circuit of the pulse solenoid valve to acquire the differential current signal in the control circuit and convert the differential current signal into a stable voltage signal; The microprocessor module is connected to the output of the signal acquisition module and has a built-in fast Fourier transform algorithm to determine the on / off state and fault state of the solenoid valve based on the received voltage signal. A status indicator module, connected to the output of the microprocessor module, is used to display the judgment result of the microprocessor module through indicator lights of different colors; The communication module is connected to the communication interface of the microprocessor module and is used to send the judgment result of the microprocessor module to the controller in real time.

[0005] Specifically, the signal acquisition module uses a signal acquisition chip, which is equipped with differential signal input pins and signal output pins. The differential signal input pins are used to acquire the RS+ and RS- differential signals in the control loop, and the processed data signals are output through the signal output pins.

[0006] Specifically, the differential signal input pins of the signal acquisition chip are pins 4 and 5, and the signal output pin is pin 2.

[0007] Specifically, the formula for the Fast Fourier Transform algorithm is: in, For length is The time-domain sampled signal; For the corresponding frequency domain representation, reflecting the first The complex amplitude of each frequency component; These are complex exponential basis functions, representing the twitch factor; It is the imaginary unit; N represents the total number of samples. Specifically, the status indicator module includes indicator lights of three colors: The green indicator light is used to indicate that the detector is in normal working condition; The blue indicator light is used to indicate that the pulse solenoid valve has successfully closed. The yellow indicator light is used to indicate a malfunction in the pulse solenoid valve.

[0008] Specifically, the status indication module and the communication module are configured to output the judgment result simultaneously. While the indicator light is displayed, the communication module sends the corresponding status code data to the external controller.

[0009] Specifically, the microprocessor module is connected to a download simulation interface for program download and online simulation.

[0010] Specifically, the microprocessor module uses a low-power 32-bit ARM architecture microcontroller, and the communication module is a serial communication module built into the microcontroller.

[0011] Specifically, the microprocessor module is connected to a reset circuit, which consists of resistors and capacitors.

[0012] Compared with the prior art, the automatic detection instrument for the switching state of a low-power pulse solenoid valve of the present invention has at least the following beneficial effects: This invention allows for non-destructive installation without altering existing equipment. No structural or circuit modifications to the original controller or pulse solenoid valve are required. The detector can be connected in series with the existing control circuit to operate, greatly reducing the deployment threshold and modification costs.

[0013] This invention is based on the detection principle of calculating magnetic flux from current changes, enabling real-time and accurate determination of the actual on / off state of the solenoid valve. Even if the controller issues a valve-closing command, the user can confirm in real time whether the valve is truly closed via indicator lights or remote communication, fundamentally eliminating the key cause of gas accidents—the valve not being closed—and shifting from passive emergency response to proactive status warning.

[0014] By analyzing the amplitude, duration, and trend of the current waveform, various fault types can be identified, such as short circuit in the solenoid valve coil, open circuit in the coil, incomplete valve core engagement, and mechanical jamming. When a fault is detected, the fault indicator light illuminates, and the fault code and specific cause of the fault can be uploaded to the gas company or property management via a wireless communication module, significantly reducing the workload of manual troubleshooting.

[0015] It adopts an ultra-low power 32-bit microcontroller, with extremely low standby power consumption. It can operate for a long time by battery power, making it particularly suitable for residential gas pipelines and renovation scenarios in old communities where there is no external power supply, reducing installation costs and maintenance difficulties. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the process structure of the present invention; Figure 2 This is the signal acquisition circuit diagram of the present invention; Figure 3 This is the circuit diagram of the indicator light of the present invention; Figure 4 This is a circuit diagram of the communication module of the present invention; Figure 5 This is the microcontroller circuit diagram of the present invention; Figure 6 This is a circuit diagram of the microcontroller program download and simulation interface of the present invention; Figure 7 This is a diagram of the microcontroller reset circuit of the present invention; Figure 8 This is a schematic diagram of the working process of the controller, detector and pulse solenoid valve of the present invention. Detailed Implementation

[0017] The automatic detection instrument for the switching status of a low-power pulse solenoid valve according to the present invention will be described in more detail below with reference to the accompanying drawings and specific embodiments.

[0018] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0019] This embodiment discloses an automatic detector for the switching status of a low-power pulse solenoid valve, such as... Figure 1-8 As shown, including The signal acquisition module is used to be connected in series in the control circuit of the pulse solenoid valve to acquire the differential current signal in the control circuit and convert the differential current signal into a stable voltage signal; The microprocessor module is connected to the output of the signal acquisition module and is used to determine the on / off state and fault state of the solenoid valve based on the received voltage signal. A status indicator module, connected to the output of the microprocessor module, is used to display the judgment result of the microprocessor module through indicator lights of different colors; A communication module, connected to the communication interface of the microprocessor module, is used to send the judgment result of the microprocessor module to the controller in real time; The detector is connected in series between the controller and the pulse solenoid valve without changing the original circuit. When the controller sends an open or close valve pulse, a transient differential current is generated in the circuit. The signal acquisition module captures this tiny current signal and converts it into a stable voltage signal. The microprocessor module receives the voltage signal, runs the built-in algorithm, and determines whether the solenoid valve is successfully opened, successfully closed, or has malfunctioned based on the principle of calculating the change in magnetic flux according to the change in current. The status indicator module displays the status on-site through different colored lights, and the communication module sends the judgment result to the controller in real time to realize closed-loop control or alarm.

[0020] The signal acquisition module uses a signal acquisition chip, which is equipped with differential signal input pins and signal output pins. The differential signal input pins are used to acquire the RS+ and RS- differential signals in the control loop, and the processed data signals are output through the signal output pins.

[0021] The differential signal input pins of the signal acquisition chip are pins 4 and 5, and the signal output pin is pin 2.

[0022] The status indicator module includes indicator lights of three colors: The green indicator light is used to indicate that the detector is in normal working condition; The blue indicator light is used to indicate that the pulse solenoid valve has successfully closed. The yellow indicator light is used to indicate a malfunction in the pulse solenoid valve. On-site inspectors do not need any instruments; they can tell the valve status and the working status of the detector just by looking at the indicator light color. The three light colors are in line with industrial practices.

[0023] The microprocessor module acquires the voltage signal output by the signal acquisition module at a high frequency, and calculates the change in magnetic flux based on the change in current in the circuit by analyzing the amplitude, duration, and trend of the voltage signal. Here, the relationship between magnetic flux and current in the coil is used through Faraday's law of electromagnetic induction and Ampere's circuital law. The change in current will cause a change in magnetic flux to determine whether the solenoid valve is in an open, closed, or faulty state. This realizes indirect measurement from current to magnetic flux without the need to add a magnetic sensor. High-frequency sampling ensures that transient details are not lost, improving the accuracy of judgment.

[0024] Based on the operating characteristics of microcontrollers, the Fast Fourier Transform (FFT) was adopted. The core formula of the FFT is based on the Discrete Fourier Transform (DFT), and the formula is as follows: in, For length is The time-domain sampled signal is the current value; For the corresponding frequency domain representation, reflecting the first The complex amplitude of each frequency component; These are complex exponential basis functions, representing the twitch factor; It is the imaginary unit; N represents the total number of samples. The time-domain signal sampled by the microcontroller... The frequency domain value of the signal can be calculated based on the above formula. By analyzing the sampling period and running time, the signal changes in the solenoid valve control circuit can be accurately reflected. Then, by comparing these changes with the standard valve closing signals and fault signals in the database, it can be deduced whether the pulse solenoid valve is properly closed.

[0025] The status indication module and the communication module are configured to output the judgment result simultaneously. While the indicator light is displayed, the communication module sends the corresponding status code data to the external controller. Local inspection and remote monitoring obtain status information synchronously without interfering with each other, avoiding inconsistencies between local indicator lights and remote data due to communication delays or failures.

[0026] The microprocessor module is connected to a download simulation interface for program download and online simulation. The microprocessor module has an interface that allows selection of SWD, JTAG, or a dedicated header for burning program code and performing online debugging simulation. Through the download simulation interface, developers or maintenance personnel can burn the compiled firmware into the microcontroller, or view variables, set breakpoints, and run the program step by step in real time in the debugger, which facilitates debugging during product development and firmware upgrades or parameter calibration after-sales service.

[0027] The microprocessor module uses a 32-bit ARM architecture low-power microcontroller, specifically the HC32L021C8P8. The communication module is a built-in serial communication module of the microprocessor module. The communication module directly uses the microcontroller's built-in serial port. The microcontroller's built-in serial communication module directly outputs the controller that receives TTL level data through the TXD and RXD pins, eliminating the need for a communication chip, reducing cost, power consumption, and simplifying the circuit.

[0028] The microprocessor module is connected to a reset circuit, which consists of a resistor and a capacitor. One end of the resistor is connected to the power supply, and the other end is connected to the reset pin and the positive terminal of the capacitor. The negative terminal of the capacitor is grounded. When the power is applied, the capacitor is charged. The reset pin remains at a low level for a period of time and then becomes a high level, realizing automatic reset of the microcontroller upon power-up. The above reset circuit is simple, low in cost, and highly reliable, and does not require a dedicated reset chip.

[0029] During installation, the detector is connected in series to the circuit between the controller and the pulse solenoid valve. The differential control signal from the controller first enters the differential input terminal of the signal acquisition chip U2. U2 internally amplifies and filters the small differential voltage with high gain and high common-mode rejection ratio, and finally outputs a stable single-ended voltage signal corresponding to the change in loop current from its second pin. This signal is then sent to the analog input pin of the microcontroller U1, achieving high-fidelity acquisition and amplification of the small current signal in the coil circuit. U1 is a domestic high-performance, low-power microcontroller HC32L021C8P8, which integrates a 12-bit ADC and a fast comparator. The P1 interface is used for program burning and online simulation. R7 and C7 form a power-on reset circuit. The microcontroller continuously acquires the voltage signal from U2 at a sampling rate of 1kHz. When the controller issues an open or close valve pulse, a transient current is generated in the pulse solenoid valve coil. The voltage signal formed by this current across the sampling resistor is captured by U2 and U1. The built-in algorithm of the microcontroller analyzes the peak value, rise slope, and attenuation characteristics of this voltage waveform, and determines the voltage signal based on the current. The direct proportionality between the rate of change and the rate of change of magnetic flux allows for the calculation of the magnetic flux change process in the solenoid valve core. This calculation result is compared with pre-stored magnetic flux change templates for normal and faulty actions to accurately determine whether the valve has successfully operated or malfunctioned. During normal standby, the microcontroller keeps the green LED constantly lit. When a valid valve-closing pulse is detected and the valve is confirmed to be closed, the microcontroller briefly illuminates the blue LED and then turns it off, simultaneously sending a successful valve-closing code to the controller via serial port. When an abnormal solenoid valve current waveform is detected after a control pulse is emitted, the microcontroller immediately illuminates the yellow fault indicator and sends a fault code corresponding to the solenoid valve number to the controller. After power-on, the detector automatically enters low-power monitoring mode, with the green indicator constantly lit. When the controller emits a valve-closing pulse, the detector quickly completes signal acquisition and algorithmic judgment, simultaneously outputting the status result through the indicator and serial port. Throughout the entire process, the detector does not experience any perceptible delay or attenuation in the transmission of the original control pulse, achieving truly lossless, real-time monitoring.

[0030] Adaptive calibration: For pulse solenoid valves of different brands or models, their current characteristics may vary slightly. To improve accuracy, an automatic calibration can be performed after initial installation: the controller sequentially sends one valve-opening pulse and one valve-closing pulse. The detector automatically records the current waveform characteristics of these two pulses and stores them in its internal non-volatile memory as a reference template for subsequent judgments. Afterward, the device can automatically and accurately perform status monitoring.

[0031] It should be noted that, in actual implementation, the structure depicted in the accompanying drawings is not a fixed or unchanging embodiment. The components of the embodiments of the invention described and shown in these drawings can typically be arranged and designed in various different configurations. Furthermore, the accompanying drawings and abstract drawings are merely illustrative and do not represent the specific structure or actual quantity in a concrete implementation.

[0032] Unless otherwise defined, the technical or scientific terms used herein should be understood in their ordinary sense as would be understood by one of ordinary skill in the art to which this invention pertains. The use of terms such as "a" or "an" in this specification and claims does not necessarily indicate a limitation of quantity. Terms such as "comprising" or "including" mean that the element or component preceding the word encompasses the element or component listed following the word and its equivalents, without excluding other elements or components. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0033] The exemplary embodiments of the present invention have been described in detail above with reference to preferred embodiments. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the concept of the present invention, and various combinations can be made to the various technical features and structures proposed in the present invention without exceeding the protection scope of the present invention.

Claims

1. An automatic detector for the switching status of a low-power pulse solenoid valve, characterized in that: include The signal acquisition module is used to be connected in series in the control circuit of the pulse solenoid valve to acquire the differential current signal in the control circuit and convert the differential current signal into a stable voltage signal; The microprocessor module is connected to the output of the signal acquisition module. It has a built-in fast Fourier transform algorithm and obtains the switching status and fault status of the pulsed solenoid valve by comparing the standard valve closing signal and fault signal in the database. A status indicator module, connected to the output of the microprocessor module, is used to display the judgment result of the microprocessor module through indicator lights of different colors; The communication module is connected to the communication interface of the microprocessor module and is used to send the judgment result of the microprocessor module to the controller in real time.

2. The automatic detector for the switching state of a low-power pulse solenoid valve according to claim 1, characterized in that: The signal acquisition module uses a signal acquisition chip, which is equipped with differential signal input pins and signal output pins. The differential signal input pins are used to acquire the RS+ and RS- differential signals in the control loop, and the processed data signals are output through the signal output pins.

3. The automatic detection instrument for the switching state of a low-power pulse solenoid valve according to claim 2, characterized in that: The differential signal input pins of the signal acquisition chip are pins 4 and 5, and the signal output pin is pin 2.

4. The automatic detection instrument for the switching state of a low-power pulse solenoid valve according to claim 1, characterized in that: Fast Fourier Transform algorithm formula: in, For length is The time-domain sampled signal; For the corresponding frequency domain representation, reflecting the first The complex amplitude of each frequency component; These are complex exponential basis functions, representing the twitch factor; It is the imaginary unit; N represents the total number of samples.

5. The automatic detection instrument for the switching state of a low-power pulse solenoid valve according to claim 2, characterized in that: The status indicator module includes indicator lights of three colors: The green indicator light is used to indicate that the detector is in normal working condition; The blue indicator light is used to indicate that the pulse solenoid valve has successfully closed. The yellow indicator light is used to indicate a malfunction in the pulse solenoid valve.

6. The automatic detector for the switching state of a low-power pulse solenoid valve according to claim 4, characterized in that: The status indication module and the communication module are configured to output the judgment result simultaneously. While the indicator light is displayed, the communication module sends the corresponding status code data to the external controller.

7. The automatic detector for the switching state of a low-power pulse solenoid valve according to claim 1, characterized in that: The microprocessor module is connected to a download simulation interface for program downloading and online simulation.

8. The automatic detector for the switching state of a low-power pulse solenoid valve according to claim 3, characterized in that: The microprocessor module uses a low-power 32-bit ARM architecture microcontroller, and the communication module is a serial communication module built into the microcontroller.

9. The automatic detector for the switching state of a low-power pulse solenoid valve according to claim 3, characterized in that: The microprocessor module is connected to a reset circuit, which consists of resistors and capacitors.

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